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locks: move i_lock acquisition into generic_*_lease handlers

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Now that we have a saner internal API for managing leases, we no longer
need to mandate that the inode->i_lock be held over most of the lease
code. Push it down into generic_add_lease and generic_delete_lease.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Jeff Layton 2014-08-22 18:50:48 -04:00
parent 1c7dd2ff43
commit f82b4b6780
3 changed files with 16 additions and 16 deletions
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6
Documentation/filesystems/Locking
View File

@ -472,8 +472,6 @@ locking rules:
All may block except for ->setlease.
No VFS locks held on entry except for ->setlease.
->setlease has the file_list_lock held and must not sleep.
->llseek() locking has moved from llseek to the individual llseek
implementations. If your fs is not using generic_file_llseek, you
need to acquire and release the appropriate locks in your ->llseek().
@ -496,6 +494,10 @@ components. And there are other reasons why the current interface is a mess...
->read on directories probably must go away - we should just enforce -EISDIR
in sys_read() and friends.
->setlease operations should call generic_setlease() before or after setting
the lease within the individual filesystem to record the result of the
operation
--------------------------- dquot_operations -------------------------------
prototypes:
int (*write_dquot) (struct dquot *);

5
Documentation/filesystems/vfs.txt
View File

@ -895,8 +895,9 @@ otherwise noted.
splice_read: called by the VFS to splice data from file to a pipe. This
method is used by the splice(2) system call
setlease: called by the VFS to set or release a file lock lease.
setlease has the file_lock_lock held and must not sleep.
setlease: called by the VFS to set or release a file lock lease. setlease
implementations should call generic_setlease to record or remove
the lease in the inode after setting it.
fallocate: called by the VFS to preallocate blocks or punch a hole.

21
fs/locks.c
View File

@ -1330,6 +1330,8 @@ static void time_out_leases(struct inode *inode)
struct file_lock **before;
struct file_lock *fl;
lockdep_assert_held(&inode->i_lock);
before = &inode->i_flock;
while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) {
trace_time_out_leases(inode, fl);
@ -1590,6 +1592,8 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
return -EINVAL;
}
spin_lock(&inode->i_lock);
time_out_leases(inode);
error = check_conflicting_open(dentry, arg);
if (error)
goto out;
@ -1655,6 +1659,7 @@ out_setup:
if (lease->fl_lmops->lm_setup)
lease->fl_lmops->lm_setup(lease, priv);
out:
spin_unlock(&inode->i_lock);
if (is_deleg)
mutex_unlock(&inode->i_mutex);
if (!error && !my_before)
@ -1672,6 +1677,7 @@ static int generic_delete_lease(struct file *filp)
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
spin_lock(&inode->i_lock);
for (before = &inode->i_flock;
((fl = *before) != NULL) && IS_LEASE(fl);
before = &fl->fl_next) {
@ -1681,6 +1687,7 @@ static int generic_delete_lease(struct file *filp)
trace_generic_delete_lease(inode, fl);
if (fl)
error = fl->fl_lmops->lm_change(before, F_UNLCK);
spin_unlock(&inode->i_lock);
return error;
}
@ -1694,8 +1701,6 @@ static int generic_delete_lease(struct file *filp)
*
* The (input) flp->fl_lmops->lm_break function is required
* by break_lease().
*
* Called with inode->i_lock held.
*/
int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
void **priv)
@ -1712,8 +1717,6 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
if (error)
return error;
time_out_leases(inode);
switch (arg) {
case F_UNLCK:
return generic_delete_lease(filp);
@ -1750,16 +1753,10 @@ EXPORT_SYMBOL(generic_setlease);
int
vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
{
struct inode *inode = file_inode(filp);
int error;
spin_lock(&inode->i_lock);
if (filp->f_op->setlease)
error = filp->f_op->setlease(filp, arg, lease, priv);
return filp->f_op->setlease(filp, arg, lease, priv);
else
error = generic_setlease(filp, arg, lease, priv);
spin_unlock(&inode->i_lock);
return error;
return generic_setlease(filp, arg, lease, priv);
}
EXPORT_SYMBOL_GPL(vfs_setlease);